In this article, we’ll be sharing with you everything you need to know about the constellation of Crater, including how to find it, deep space objects contained within it and how to use it to find other night sky objects more easily.

The Constellation of Crater 

Crater, which means ‘the cup’ in Latin, is one of the constellations that Greek astronomer Ptolemy cataloged over 2,000 years ago.

In Greek mythology, Crater is the god Apollo’s cup. Corvus (the Crow) was tasked with taking the cup, filling it with water and bringing it back to Apollo. Corvus became distracted by some figs and stopped to wait for them to ripen.

Eventually Corvus took the cup of water of Apollo. Corvus knew Apollo would be angry so he blamed Hydra (the water snake) for the delay. Apollo knew Corvus was lying and in his anger threw Corvus, Crater and Hydra into the sky.

Apollo scorched Corvus’ feathers to make him eternally thirsty and placed him within sight of Crater. Corvus can never drink because Hydra guards Crater.

To help you spot Crater, here’s what SkySafari 6 shows.

Crater as shown by SkySafari
Crater as shown by SkySafari. Click for full-screen.

Crater has an area of 282 square degrees making it the 53rd largest of the 88 recognized constellations. Crater is often depicted as a two-handed chalice.

The boundaries and neighboring constellations for Crater
The boundaries and neighboring constellations for Crater. Click for full-screen.

In the next section discover how to find Crater.

How To Find Crater In The Night Sky

Crater is part of the Hercules family of constellations. It’s located in the southern sky and is visible to observers at latitudes between +65° and -90°. Northern Hemisphere observers and Southern Hemisphere observers can see it best in April.

The constellation of Crater is bordered by the constellations Corvus, Hydra, Leo, Sextans and Virgo

Crater at 10:00 p.m. on the 2nd of May
Crater at 10:00 p.m. on the 2nd of May. Click for full-screen.

To find Crater, do a naked-eye search for Leo. Identify Regulus (Alpha Leonis), at the base of the Sickle asterism, then draw an imaginary line ~32° long south from Regulus to Delta Crateris. 

Alternatively, do a naked-eye search for Hydra. Identify Alphard (Alpha Hydrae) then draw an imaginary line ~11° long northwest from Alphard to Lambda Hydrae then extend this line ~16° to Delta Crateris.

A third option is to do a naked-eye search for Corvus. Identify Algorab (Delta Corvi) then draw an imaginary line ~17° long southeast from Algorab to Delta Crateris. 

You can measure all of these angular distances with your hand at arm’s length (link opens a new tab).

To find Crater’s exact position for your location on any night, use software such as Stellarium (free) or SkySafari.

Crater’s Brightest Stars 

Crater is a small, faint constellation and, as such, doesn’t contain many stars brighter than magnitude five.

All the ones it does contain are shown in the star chart below and written about in more detail beneath that.

The brightest stars of Crater
The brightest stars of Crater. Click for full-screen.

Alpha Crateris (Alkes) – This magnitude 4.07, orange giant is 175 light-years away. Alkes is the second brightest star in Crater. Its mass is 2.5 Solar masses and its radius is 13.0 Solar radii. ‘Alkes’ means ‘the wine cup’ in Arabic and this star marks the western corner of the stem.

Beta Crateris – This magnitude 4.46, white giant is 340 light-years away. Its mass is 3.2 Solar masses, its diameter is 4.6 Solar diameters and it’s 1.8 times hotter than the Sun. This star marks the eastern corner of the stem.

Gamma Crateris – This double star is the third brightest star in Crater. The magnitude 4.07, yellow-white, main sequence, primary and magnitude 7.90, secondary component are 25.2 arcseconds apart. Gamma Crateris is 89 light-years away.

Delta Crateris (Labrum) – This magnitude 3.56, orange giant is 195 light-years away. Labrum is the brightest star in Crater. Its mass is 2.5 Solar masses and its radius is 13.0 Solar radii. ‘Labrum’ is a Latin title for the Holy Grail and this star marks the bottom of the bowl.

Epsilon Crateris – This magnitude 4.80, orange-red giant is 376 light-years away. Its mass is 1.2 Solar masses, its diameter is 36.6 Solar diameters and it’s 30% cooler than the Sun. 

Zeta Crateris – This double star is 353 light-years away. The magnitude 4.71, yellow-orange, giant, primary and magnitude 7.84, secondary component are 0.3 arcseconds apart. This may be a multiple system.

Eta Crateris – This magnitude 5.17, blue-white, main sequence star is 251 light-years away. This eruptive variable has an unknown magnitude range and period. Its mass is 2.9 Solar masses, its diameter is 2.5 Solar diameters and it’s 1.7 times hotter than the Sun.

Theta Crateris – This double star is 280 light-years away. The magnitude 4.69, blue-white, main sequence, primary and magnitude 17.90, secondary component are 177.9 arcseconds apart. This may be a multiple system. 

Lambda Crateris – This magnitude 5.07, yellow-white, giant is 140 light-years away. Its mass is 1.3 Solar masses, its diameter is 2.6 Solar diameters and it’s 1.3 times hotter than the Sun. 

Star Hopping From Crater 

Crater is too dim to be the starting point for beginner star hops.

Objects To See Within Crater 

Crater contains no Messier objects and no other deep sky objects suitable for small telescope users. 

Summary

Crater is a dim constellation containing only a few notable stars and no deep sky objects for small telescope users. Look for it near Corvus and Hydra this spring. 

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